Technical Field
The present invention relates to a color processing apparatus, an inspection apparatus, and a color processing method.
Background Art
While printed matter had been inspected manually in the past, an inspection apparatus that inspects printed matter automatically has become popular as a post-production process of printing recently. In the inspection apparatus, first, a master image as a reference is generated from image data to be printed. Subsequently, the inspection apparatus compares the generated master image with a scanned image of the printed matter to be inspected to determine failure of the printed matter based on a grade of difference between them
The master image is generated by converting a print image (a bitmap image) in Cyan, Magenta, Yellow, and Key plate (CMYK) format generated from the image data to be printed into a print image (a bitmap image) in Red, Green, and Blue (RGB) format as a scanned image format. A color conversion table is used for converting color space of an image into different color space such as the conversion from the print image in CMYK format into the print image in RGB format described above.
The color conversion table described above is generated by associating the print image in CMYK format of a color chart including various graded color patches with a scanned image in RGB format generated by scanning a print sheet on which the print image if printed. More specifically, the color conversion table is generated by mapping colorimetric values of color patches on the print image onto colorimetric values of color patches on the scanned image.
To generate an accurate color conversion table, it is necessary that a part of a scanned image of a color chart, i.e., a scanned image of a color patch, has no failure. To check if the scanned image of the color patch has no failure, a technology that compares colorimetric values of the scanned image of the color patch as a reference value with colorimetric values of other color patches is known.